Good comparison between the 4. Rackspace has come a long way since we evaluated them a few years ago (they wanted like 24 hours to bring up a new instance/serv

Good comparison between the 4. Rackspace has come a long way since we evaluated them a few years ago (they wanted like 24 hours to bring up a new instance/server for us back then, so we ended up going with AWS). Generally speaking our biggest challenges with AWS have been storage (making TBs of web content securely available to various autoscaling clusters) and network i/o (especially across VPC/public internet boundaries). We've actually found that AWS' pricing beats the costs of hosting internally, especially once you look beyond raw server cost and factor in power/cooling/manual labor/datacenter space/etc. And there are lots of different options for monitoring your usage to avoid surprises (we're looking into programmatic usage reports and New Relic for that, though we've been there a couple years now so we have a good idea what our bills are going to run each month). As far as CDN, we get way better pricing from Level3 and Akamai than we could from CloudFront or Rackspace, but our traffic patterns are more 95th-percentile-friendly than most.